Zusammenfassung der Ressource
Biology (level 1)
- Natural Selection
- Process by which organisms with variations
most suited to their local environment survive
and leave more offspring.
- It occurs in any situation in which more individuals are born
that can survive, there is natural heritable variation, and there
is a variable fitness among individuals.
- Ex. If there are green grasshoppers and brown
hoppers that live on grass, the green grass hoppers
will survive and reproduce because of camouflage.
- The grasshoppers' predators (for example a bird) will spot the
brown grasshoppers more easily and the brown grasshoppers
will have a hard time surviving and reproducing.
- This means that the green grasshoppers will become more common than brown
grasshoppers overtime because green grasshoppers will reproduce more green
grasshoppers and the brown grasshoppers will be unable to reproduce at the
same rate since the population of brown grasshoppers will decrease.
- Fitness
- How well an organism can survive
and reproduce in its enviroment
- Adaptations is a big factor in fitness
- Survival of the fittest is the difference in
rates of survival and reproduction
- Adaptations
- Any heritable characteristic that
increases an organism's ability to
survive and reproduce in its enviroment
- They can involve body parts or structures,
colors, physiological functions, or behaviors
- Lethal Alleles
- Alleles are the different forms of a gene
- Lethal alleles can get passed on in a
gene pool like regular alleles.
- Mutations
- Heritable changes in genetic information
- The affect of mutations on genes vary widely
- Some have little or no effect
- Some produce beneficial variations
- Some negatively disrupt gene function
- Often they produce proteins with new or altered functions that can be
useful to organisms in different or changing enviroments